Field of the Invention
Devices, systems, and methods consistent with the invention relate to welding with cladding and curtain electrodes.
Description of the Related Art
Cladding with strip electrodes is known in the industry. Typically strip electrodes are used for cladding because of their large width and low penetration resulting in a large cladding area but low admixture with the base metal. This is especially true of electro-slag cladding. However, as the penetration is minimized, there is a risk of lack of penetration or even inclusions at the edges of the clad deposit especially where the deposit intersects with a previous adjacent deposit. If found, these inclusions require repair, if left unchecked, these inclusions can result in premature failure of the cladding layer. Further, when cladding with strip electrodes it is desirable to increase the width of the strip electrode to clad larger areas faster. However wider strip electrodes require significantly more current to apply. These high currents produce magnetic fields that become concentrated at the ends of the strip. These highly concentrated magnetic fields disturb the puddle and can force liquid metal from the edges of the weld deposit toward the center. In extreme cases, electro-magnetic steering devices are used to introduce a counter rotating magnetic fields to cancel some of the adverse affects of concentrated high magnetic fields at the edge of the strip electrode.